Improvement in counter-sink



ifm. @ein @met P. A, WHITNEY, O-F WOO'S'DSTOCK, VERMONT.

Letters Patent No."8'3,348, dated Octobccl 20, 1868; antedated October 16, 1868.

IIVIPRQVENIENT IN COUNTER-SUNK.

uw* The Schedule referred to in these Letters Patent and making part of the same.

To all 'whom ttmay concern:

Be it known that 1,1). A. WH1TNEY,-of Woodstock, in the county of Windsor, and State of Vermont, have tinvented a Inew,` and useful Improvement in Counter Sinks; and I do hereby declare that the following is a full, clear, and exact-description thereof', which will enf able those skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this Kspeciiication.

My invention relates to an improvement in countersinks or reamers for metal, and consists in the arrange ment, within a`hollo`w stock, of the cutter, which isl made of a piece of lat steel, between two clampingnose pieces, through which it is fed `downward by a feeding-screw, as it wears away, as will bemore fully described on reference to the drawingsmakng part of this specication, inv which y Figure l represents an end view of my improved reamer, and

Figure 2, a longitudinal section through the centre of the same.

Similar letters of reference indicate corresponding parts.

A represents the stock, having a central circular passage through its whole length, 'considerably enlarged at the lower end. A

B B are semi-circular clamping-jaws, having the lower ends tapered, to agree with the taperof the cutter, and a longitudinal hole in the other end, to allow the feedscrew D to work, to feed the cutter as it becomes shorter, by reason of v wear.

D is the feedscrew,-which Works in the screwed upper end of the centralopening in the stock.

G is the cutter, which consists of a simple flat piece of steel, having the lower end ground to the proper taper and angle,`and which'fits a ilat groove in the faces of the semicircular clamping-pieces B B, which have a screwed portion, E, to correspond with the internal screw in the lower end of the stock.

This screw-joint 4is made slightly tapering, so that,

, when ,screwed up, the parts B B will hold the cutter between' them sufficiently tight to prevent any trembling or clatteringof the cutters.

The tapered points of the parts `B B form a guide"- the chips.

for the' cutter, which prevents the cutting-edges of the same from chattering as it is performing its work. It also prevents the cutter being fed into the 'work too' fast, limiting the amount of the same to the distance which the cutter projects beyond the said tapered point. Portions of the said tapered point are removed, as 'shown at -a a, to allow a passage fornthe discharge of The shank A of the stock is inserted in the mandrel of the drill-press when it is set to work.

' It will be obvio us from the foregoing description that my improved reamer 'or counter-sink possesses several advantages over those now in use; as, for instance, the cutter is very easy and simple-of construction, and may be tempered throughout its whole length, and will last a great length of time, and, when woruout, is readily .replaced by a; new one, and the arrangement of the tapered point, to. govern the depth of cut, and to serve as a guide 'to the cutter, to compel it to out smoothly and truly, is very important.

It is well known that in reaming or counter-sinking metal with a tool having two cutting-edges, one edge will frequently meet greater' resistance than the other, which will cause the tool to spring, and perhaps react against the said other edge, and drive that into the metal on its side of the hole, until, by that means, the former iinds relief, and passes the point of great resistance, when the tool will spring back again, causing that edge to cut deeper than it should, until iinally the tool is set into such a chattering and unsteady action, that it is impossible to do the work smoothly or truly, all of which is avoided, in my improved implement, by the tapered guide-point. I

Having thus fully described my invention,

What I claim,- and desire-to secure by Letters Patent, isl The herein-described improved counter-sink, when n constructed substantially as and for the purpose described.

P. A. WHITNEY. v lWitnesses:

WM. D. FOSTER, WILLIAM E. JOHNSON. 

